Efficient Low Cost Process For Single Step Metal Forming of 3D Interconnected Above-IC Inductors

Ayad Ghannam (1) , Lamine Ourak (1) , David Bourrier (2) , Christophe Viallon (1) , Thierry Parra (1)

1 LAAS-MOST - Équipe Microondes et Opto-microondes pour Systèmes de Télécommunications
2 LAAS-TEAM - Service Techniques et Équipements Appliqués à la Microélectronique

This paper presents a novel and efficient low cost process capable of integrating high-Q above-IC inductors and their interconnects using a single electroplating step. It relies on the SU8 and BPN resist as well as an optimized electroplating technique to form the 3D interconnected inductor. The SU8 is used to form a thick layer located underneath the inductor to elevate it from the substrate. Then, the BPN is used as a high resolution mold (16:1) for copper electroplating. Standard or time optimized electroplating is later used to grow copper in a 3D manner, making the transition between all metallic layers straight forward. High-Q (55 @ 5 GHz) power inductors have been designed and integrated above an RF power LDMOS device using this process. Finally, the process capabilities are demonstrated by integrating a solenoid inductor using only two lithography masks and a single electroplating step.

Mots clés: Inductors; Copper; 3D Copper; Interconnect; SU8; BPN; LDMOS; Above-IC

Domaines: Electromagnétisme

Ayad Ghannam, Lamine Ourak, David Bourrier, Christophe Viallon, Thierry Parra. Efficient Low Cost Process For Single Step Metal Forming of 3D Interconnected Above-IC Inductors. 41st European Solid-State Device Research Conference (ESSDERC 2011), Sep 2011, Helsinki, Finland. 4p. ⟨hal-00627894⟩